Sheet metal yoke and process of making same



Dec. 3, 1935. E. A. CONNER 2,022,801

SHEET METAL YORE AND PROCESS OF MAKING SAME Filed June 15, 1932INVENTOR. E wARD/LC'QNNER,

Patented Del; 3, 1935 PATENT OFFICE aozasoi snEE'r METAL roxr: Annmocsss or name sum:

Edward A. Conner, Stratford, Conn. assig'nor to American Chain Company,Inc., a corporation of New York Application June 15, 1932, Serial No.617,288

16 Claims. (Cl. 29-148) This invention relates to attachmentsfor sucharticles as wires, rods and the like, and has for its general object theprovision of an attachment in the nature of a yoke with a shank ofrod-like form which can bereadily secured metallically in butt relationwith the rod, wire or the like to which it is to be united, as by a buttwelding operation.

A more particular object of the invention is to provide an improvedprocess for making yokes or like attachment members with rod-like shanksof the above character from blanks of sheet metal, in such manner and bysuch steps that great economy of labor and material is secured.

Another object ofthe invention is to provide a yoke or attachment oftheabove improved type .with an attaching shank which can be so weldedto the rod, wire, or other article to which it is to be united, that theunion will develop a strength equal to, or exceeding, that of said wireor rod.

The above and other features of the invention are illustrated anddescribed fully in the accompanying drawing and specification and arepointed cut'in the claims.

In the drawing;

Figure 1 is a view in plan, andFig. 2 is a view in side elevation, of ablank suitable for use in forming the attachment of the presentinvention;

Figs. 3 and 4 are similar views showing the blank partly shaped;

Figs. 5 and 6 show the blank at a subsequent stage of its formation; andFig. 7 isa view in end elevation looking toward the bottomof Fig. 6;

Fig. 8 is a view in side elevation of the. yoke o attachment in finalform; 1

Fig. 9 shows the same secured metallically by a butt weld to the end ofa rod or wire;

Fig. '10 is a view'in end elevation looking toward the bottom end ofFig. 8; v I

Fig. 11 is a view in side elevation of another form of attachment havingflanged eyelets inthe yoke portion and having an externally threadedFigs. 12 to 15 inclusive are fragmental views in section showingprogressive stages in the for:

mation of the eyelets;

Fig. 16 is a view in side elevationof still anotherform of attachmenthaving an internally threaded tubular shank; and

Figs. 17 and 18 are views in longitudinal section showing .two stages inthe formation of an attachment having a completely solid shank. y

In a now preferred embodiment of the invention selected for illustrationand description, an attachment or yoke is illustrated which, in itsfinal form, may be desirably of substantially the general shape shown inFig. 8, comprising a yoke portion adapted for removable attachment toany suitable article with which such attachment is to be eifected, and ashank or portion which is adapted to be permanently secured metallicallyin butt relation with a rod, wire or the like.

In pursuance of the invention, the above at:

.tachment is made of sheet metal by an improved process which in itspreliminary stages may be I substantially that disclosed in U. S.Letters Patent No. 1,770,971, these earlier stages being briefly asfollows:

In Figs. 1 and 2 there is shown a fiat metallic blank ID of a shapesuitable to be formed into an 1 attachment havi g the final formillustrated which; when brought into axial alinement, are 20 adapted toreceive a bolt (not shown), or other suitable form of means by which thedevice may be secured removably to any article with which it is desiredto effect such a union.

The next stage comprises the further bending 2 or folding of thelongitudinal margins l2 of the blank around to form a shank which is ofsubstantially cylindrical cross-section as shown in Fig. 7; this bendingbeing carriedto an extent which brings into contact the marginalprotuberances l4 and i5 which are provided to enable this bendingoperation to be accomplished rapidly, with accuracy, .and withoutspecial care or expenditure of time and skill by the operator.

At this stage of the process the sheetmetal of the blank at the end ofthe shank presents a form when viewed from a direction looking towardthe bottom of Fig. 6, that is substantially like the ring shown in Fig.7, with walls 18 which are relatively thin as compared with the centralspace left by the bending operation up to this stage.

In general, the above stages may be, and preferably are,.substantiallyas recited in the abovementioned Patent No. 1,770,971.

In the further treatment of the blank, ac- 5 .cording to the presentinvention, the folded sheet metal shank portion of the attachment.member is subjected to an impacting or compressing operation which ispreferably carried out by a seriesof rapid velocity blows, the impactingforces being applied successively around the; periphery of the shank, asfor example, in

a rotary swaging machine of the type known as a Flo-former, disclosed incopending application Serlal No. 500,710;

The impacting operation is carried to an extent which results in flowingthe material of the sheet metal walls inward increasing the wallthickness and reducing the bore until the shank consists wholly 'of thematerial of the walls, the

bore being reduced to the negligible size shown to which it is desiredto eifect the permanent attachment of the yoke herein illustrated. The

' rotary swaging machine also produces a substantially uniformthickening of the wall of the shank in any cross-section. I

In Fig. 9, the said yoke is shown as butt welded to the end of a metalrod H, the weld being indicated at i9.

From the foregoing description, it will be evident thatby this novelprocess, provision has been' made for making rapidly and accurately fromsheet metal a yoke' or attachment with a shank composed of a bent-up andcompacted portion of the sheet metal and which has all the desirablecharacteristics embodied in a yoke made by the relatively more expensivemanufacturing process of forging, the present invention making itpossible to utilize sheet metal not only for the yoke portion, but alsofor the shank portion, both of which can be bent up readily in dies by apreliminary operation which brings the material of the shank into shapefor the swaging operation, the latter being accomplished as abovedescribed rapidly and accurately by the flo-forming of the shank.

It has been found that it is not desirable to butt weld the cylindricalform of shank which exists at the stage shown in Fig. 7, as that yieldsat best a union of relatively low strength, but that by carrying out aprocess of impactment such as -that hereinbefore described, until theshank is impacted into a substantially solid rod, a yoke is providedwith an integral sheet-metal shank adapted to be butt welded and whichwill yield a union of maximum strength.

In Fig. 11, I show an attachment 20 similar in general form to thatshown in Fig. 8, but diifering therefrom in two details: the shank 2| ofthe attachment 2!! is externally threaded so that it may be screwed intoa socket, while the yoke 22 of said attachment is formed withflangedeyelets 23. The threads in the shank may be either rolled or cut,as desired. The shank 2! like the shank I6 is nearly solid, and, as aresult of the impacting or swaging process, the wall thickness sincreased. The thread is cut or otherwise formed in the shank to a depthapproximately canal to the increase in wall thickness so that there isno weakening of the shank by the threads. ,The eyelets 23 are preferablyformed in successive stages, as illustrated in Figs. I 2 to IS inelusive. First the metal is punched as shown in Fig. 12 to form anaperture 24. In the next step the metal surrounding the aperture iscupped outwardly, as shown in Fig. 13. In the third stage, themetal isbelled outward enlarging the aperture 24 and forming a substantiallycylindrical flange with a well-rounded inner shoulder '25 and a fillet26 on the outside of substantial shoulder so that the finished eyelethas the form shown in Fig. 15. This form of eyelet provides a broadbearing surface for a bolt or pin.

The attachment 21 shown in Fig. 16 differs from attachment 20 only inthe form 01' its shank,

and in making the attachment, the steps illustrated in Figs. 1 to 6 areemployed. However, that portion of the blank which is to form the shank28 is wider, so that when the. blank is folded to substantially the formshown in Fig. 6, 6

a shank of larger diameter is provided. This shank is then put through aswaging operation on a-m'andrel (notshown) and is reduced in diameterbysuch swaging operation, so that the wall thickness of the shank isincreased, while at 10 the same time an iimer bore 29 is maintainedtherein by the mandrel. The swaging operation isv such as to increasethe thickness of the wall suificiently to permit of cutting a thread inthe bore of the shank 28, such increase in thickness 15 approximatingthe depth of the thread.

Figs. 17 and 18 show howan attachment 30 may be made with a completelysolid shank. The construction of the attachment is similar to that shownin Fig. 16, but, in place of swaging 20 its shank 3| upon a removablemandrel, a pin 32 is inserted in the shank and the latter is then swageddown upon the pin. In the swaging operation, not only is the outsidediameter of the shankreduced, but the pin also is reduced in diameter inthe main body portion of the shank. However, the pin extends upward intothe out wardly flaring portion 33 of the shank and during the swagingportion, a head 34 is formed on s the pin 32, said head 'conforming intaper to 30 the tapered portion 33 of the shank. The pin is thus firmlyanchored in the shank and is'retained therein not only by frictionalengagement with the shank, but also by reason of the head 34 formedthereon. The finished attachment 35 thus provides a completely solidshank which maybe welded to a'rod, or other member, as shown in Fig. 9,or, which may be externally threaded for engagement with the socketmember.

Having thus described my invention, what I 40 claim as new and desire tosecure by Letters Pat ent is as follows:

1. The process of forming an attachment member of the class described,said process comprising the steps of bending a portion of a blank offiat 415 sheet metal into the form of a cylinder, compacting saidcylinder radially inward to'increase the wall thickness thereofsubstantially uniformly and cutting a thread in said thickened wall to adepth approximately equal to the increase in thickness of the wall,whereby the effective thickness of the sheet metal member will remainsubstantially uniform throughout.

2. The process of formingan attachment member of the class described,said process comprising the steps of bending a portion of a blank offlat sheet metal in the form of a split cylin-' der, compacting saidcylinder radially inward to increase the wall thickness thereofsubstantial- 1y uniformly, and cutting an internal thread in saidcylinder to a depth approximately equal to the increase in thickness ofthe wall.

3. The process of forming an attachment member with a threaded shank,said process comprising the steps of bending a.portion of a blank of berof sheet metal with a substantially solid cylindrical shank, saidprocesscomprising the 76 the cylinder and increase the wallthicknessthereof, and continuing the impacting until said cylinder isformed into a substantially solid shank.

5. The process of forming an attachment member of the class described,said process comprising the steps of bending a portion of a blank offlat sheet metal into the form of a split cylinder, inserting a metalrod in the bore of said cylinder, compacting a portion of the cylinderand the enclosed rod, leaving a portion of said rod and of the enclosingcylinder uncompact'ed whereby the compacted portion of the cylinder androd will constitute a solid cylindrical shank and the uncompactedportion will resist lengthwise displacement of the rod and cylinderrelatively to each other.

-6. The process of forming an attachment member of the classdescribed/said process comprising the steps of bending a portion of ablank of flat sheet metal to form a split cylinder, inserting a metalrod in the bore of said cylinder, compacting a portion of the cylinderand the rod radially inward to form a solid cylindrical shank andcompacting another portion of the cylinder and rod in such manner as toproduce a tapering region of engagement between the rod and thecylinder.

7. An attachment member of the class described, said member beingcomposed of an integral piece of sheet metal and comprising a yokeportion and a shank portion, the yoke portion having a pair of spacedcoaxial apertures for receiving a connecting device, said shank portionbeing in the form of a split cylinder having a greater wall thicknessthan that of the yoke portion.

-8. An attachment member of the class described, said member beingcomposed of an integral piece of sheet metal and comprising a yokeportion and a shank portion, the yoke portion having a pair of spacedcoaxial-apertures for receiving a connecting device, said shank portionbeing in the form of a split cylinder having agreater wall thicknessthan that of the yoke portion, said shank portion being threaded.

9. An attachment member of the class described, said member beingcomposed of an integral piece of sheet metal and comprising a yokeportion and a shank portion, the yoke portion having a pair of spacedcoaxial apertures for receiving a connecting device, said shank portionbeing in the form of a split cylinder having a greater wall' thicknessthan that of the yoke portion, the shank portion being threaded, and thedepth of the thread being approximately equal to the excess in wallthickness of the shank portion over the yoke portion.

10. An attachment member of the class described, said member beingcomposed of an integral piece of sheet metal and comprising a yokeportion and a shank portion, the yoke portion having a pair of spacedcoaxial apertures for receiving a connecting device, said shank portionbeing in the form of a split cylinder having a greater wall thicknessthan that-of the yoke portion, the shank portion being internallythreaded.

11. An attachment member of the class described, said-member consistingof an integral piece of sheet metal comprising a yoke portion connectingmember, the shank portion being in theform of a split cylinder having awall of uniform thickness greater than that of the yoke portion, saidcylinder being internally threaded, and the depth of the thread beingapproximately equal to the excess in wall thickness of the shank portionover the yoke portion.

, and a shank portion, the yoke portion having a Y pair of spacedcoaxial apertures for receiving a 12. An attachment member of the classde- I scribed, said member consisting of an integral piece bf sheetmetal comprising a yoke portion and a shank portion, the yoke portionhaving a pair of spaced coaxial flanged eyelets for receiving aconnecting device, the shank portion being wall thickness than that ofthe yoke portion.

13. The combination with a metal rod, wire or the like, of an attachmentcomprising a member composed of a piece of sheet-metal stock having anattaching shank comprising a portion of'said sheet-metal piece disposedin the form of a compact, substantially solid cylinder with asubstantially solid end united metallically in butt to butt relationwith said rod, wire or the like, as by buttwelding.

14. The combination with a metal rod, wire or the like, of an attachmentcomprising a member composed of a piece of sheet-metal stock having anattaching shank comprising a portion of said sheet-metal piece disposedin the form of a compact, substantially solid cylinder with asubstantially solid end united metallically in butt to butt relationwith said rod, wire or the like, as by butt-welding, said sheet-metalpiece having its free end formed with an eye adapted to be connectedremovably with an article with which said rod, wire or the like is to beassociated.

15. The combination with a. metal 'rod, wire or the like, of anattachment comprising a member,

composed of a piece of sheet-metal stock having an attaching shankcomprising a portion of said sheet-metal piece disposed in the form of acompact, substantially solid cylinder with a substantially solid endunited metallically in butt to butt relation with said rod, wire or thelike, as by butt-welding, said sheet-rnetal piece having its free endformed with a plurality of eyes in spaced relation and having the eyeapertures in coaxial alinement, constituting a yoke adapted to receive aconnecting member, such as a bolt, pin or clevis, to permit removableattachment between said rod, wire or the like and an article to beassociated therewith.

16. The combination with a metal rod, wire or the like, of an attachmentcomprising a member composed of apiece of sheet metal stock having anattaching shank comprising a portion of said sheet metal piece, disposedin the form of a compa'ct, substantially solid cylinder with asubstantially solid end united metallically in butt to butt relationwith said rod, wire or the like, as by butt welding, said sheet metalpiece having its free end formed with a pair of flanged eyelets inspaced co-axial alinement, constituting a yoke adapted to receive aconnecting device, such as a bolt, pin

